Add another hardware bug workaround for Yukon II controllers that

have hardware ram buffer. The silicon bug seem to be triggered by
pause frames if receive buffer is not aligned on FIFO word(8 bytes).
To workaround the issue, make sure to align Rx buffers on 8 bytes.
Unfortunately this workaround requires yet another Rx fixup for
strict alignment architecture machines to align IP header.

For newer hardwares that lacks ram buffer may not have this bug so
check number of available ram buffer size to see the existence of
ram buffer.

Reported by:	Ian Freislich (ianf <at> clue dot co dot za), das
Tested by:	Ian Freislich (ianf <at> clue dot co dot za)

2 files changed, 62 insertions, 7 deletions

diff --git a/sys/dev/msk/if_msk.c b/sys/dev/msk/if_msk.c
index 9854b93..7e9d413 100644
--- a/sys/dev/msk/if_msk.c
+++ b/sys/dev/msk/if_msk.c
@@ -244,6 +244,9 @@ static __inline void msk_rxput(struct msk_if_softc *);
 static int msk_handle_events(struct msk_softc *);
 static void msk_handle_hwerr(struct msk_if_softc *, uint32_t);
 static void msk_intr_hwerr(struct msk_softc *);
+#ifndef __NO_STRICT_ALIGNMENT
+static __inline void msk_fixup_rx(struct mbuf *);
+#endif
 static void msk_rxeof(struct msk_if_softc *, uint32_t, int);
 static void msk_jumbo_rxeof(struct msk_if_softc *, uint32_t, int);
 static void msk_txeof(struct msk_if_softc *, int);
@@ -783,7 +786,12 @@ msk_newbuf(struct msk_if_softc *sc_if, int idx)
 		return (ENOBUFS);
 
 	m->m_len = m->m_pkthdr.len = MCLBYTES;
-	m_adj(m, ETHER_ALIGN);
+	if ((sc_if->msk_flags & MSK_FLAG_RAMBUF) == 0)
+		m_adj(m, ETHER_ALIGN);
+#ifndef __NO_STRICT_ALIGNMENT
+	else
+		m_adj(m, MSK_RX_BUF_ALIGN);
+#endif
 
 	if (bus_dmamap_load_mbuf_sg(sc_if->msk_cdata.msk_rx_tag,
 	    sc_if->msk_cdata.msk_rx_sparemap, m, segs, &nsegs,
@@ -840,7 +848,12 @@ msk_jumbo_newbuf(struct msk_if_softc *sc_if, int idx)
 		return (ENOBUFS);
 	}
 	m->m_pkthdr.len = m->m_len = MSK_JLEN;
-	m_adj(m, ETHER_ALIGN);
+	if ((sc_if->msk_flags & MSK_FLAG_RAMBUF) == 0)
+		m_adj(m, ETHER_ALIGN);
+#ifndef __NO_STRICT_ALIGNMENT
+	else
+		m_adj(m, MSK_RX_BUF_ALIGN);
+#endif
 
 	if (bus_dmamap_load_mbuf_sg(sc_if->msk_cdata.msk_jumbo_rx_tag,
 	    sc_if->msk_cdata.msk_jumbo_rx_sparemap, m, segs, &nsegs,
@@ -1041,14 +1054,16 @@ mskc_setup_rambuffer(struct msk_softc *sc)
 {
 	int next;
 	int i;
-	uint8_t val;
 
 	/* Get adapter SRAM size. */
-	val = CSR_READ_1(sc, B2_E_0);
-	sc->msk_ramsize = (val == 0) ? 128 : val * 4;
+	sc->msk_ramsize = CSR_READ_1(sc, B2_E_0) * 4;
 	if (bootverbose)
 		device_printf(sc->msk_dev,
 		    "RAM buffer size : %dKB\n", sc->msk_ramsize);
+	if (sc->msk_ramsize == 0)
+		return (0);
+
+	sc->msk_pflags |= MSK_FLAG_RAMBUF;
 	/*
 	 * Give receiver 2/3 of memory and round down to the multiple
 	 * of 1024. Tx/Rx RAM buffer size of Yukon II shoud be multiple
@@ -1412,6 +1427,7 @@ msk_attach(device_t dev)
 	sc_if->msk_if_dev = dev;
 	sc_if->msk_port = port;
 	sc_if->msk_softc = sc;
+	sc_if->msk_flags = sc->msk_pflags;
 	sc->msk_if[port] = sc_if;
 	/* Setup Tx/Rx queue register offsets. */
 	if (port == MSK_PORT_A) {
@@ -1976,6 +1992,7 @@ msk_txrx_dma_alloc(struct msk_if_softc *sc_if)
 	struct msk_rxdesc *jrxd;
 	struct msk_jpool_entry *entry;
 	uint8_t *ptr;
+	bus_size_t rxalign;
 	int error, i;
 
 	mtx_init(&sc_if->msk_jlist_mtx, "msk_jlist_mtx", NULL, MTX_DEF);
@@ -2107,9 +2124,16 @@ msk_txrx_dma_alloc(struct msk_if_softc *sc_if)
 		goto fail;
 	}
 
+	rxalign = 1;
+	/*
+	 * Workaround hardware hang which seems to happen when Rx buffer
+	 * is not aligned on multiple of FIFO word(8 bytes).
+	 */
+	if ((sc_if->msk_flags & MSK_FLAG_RAMBUF) != 0)
+		rxalign = MSK_RX_BUF_ALIGN;
 	/* Create tag for Rx buffers. */
 	error = bus_dma_tag_create(sc_if->msk_cdata.msk_parent_tag,/* parent */
-		    1, 0,			/* alignment, boundary */
+		    rxalign, 0,			/* alignment, boundary */
 		    BUS_SPACE_MAXADDR,		/* lowaddr */
 		    BUS_SPACE_MAXADDR,		/* highaddr */
 		    NULL, NULL,			/* filter, filterarg */
@@ -2918,6 +2942,23 @@ mskc_resume(device_t dev)
 	return (0);
 }
 
+#ifndef __NO_STRICT_ALIGNMENT
+static __inline void
+msk_fixup_rx(struct mbuf *m)
+{
+        int i;
+        uint16_t *src, *dst;
+
+	src = mtod(m, uint16_t *);
+	dst = src - 3;
+
+	for (i = 0; i < (m->m_len / sizeof(uint16_t) + 1); i++)
+		*dst++ = *src++;
+
+	m->m_data -= (MSK_RX_BUF_ALIGN - ETHER_ALIGN);
+}
+#endif
+
 static void
 msk_rxeof(struct msk_if_softc *sc_if, uint32_t status, int len)
 {
@@ -2955,6 +2996,10 @@ msk_rxeof(struct msk_if_softc *sc_if, uint32_t status, int len)
 		}
 		m->m_pkthdr.rcvif = ifp;
 		m->m_pkthdr.len = m->m_len = len;
+#ifndef __NO_STRICT_ALIGNMENT
+		if ((sc_if->msk_flags & MSK_FLAG_RAMBUF) != 0)
+			msk_fixup_rx(m);
+#endif
 		ifp->if_ipackets++;
 		/* Check for VLAN tagged packets. */
 		if ((status & GMR_FS_VLAN) != 0 &&
@@ -3008,6 +3053,10 @@ msk_jumbo_rxeof(struct msk_if_softc *sc_if, uint32_t status, int len)
 		}
 		m->m_pkthdr.rcvif = ifp;
 		m->m_pkthdr.len = m->m_len = len;
+#ifndef __NO_STRICT_ALIGNMENT
+		if ((sc_if->msk_flags & MSK_FLAG_RAMBUF) != 0)
+			msk_fixup_rx(m);
+#endif
 		ifp->if_ipackets++;
 		/* Check for VLAN tagged packets. */
 		if ((status & GMR_FS_VLAN) != 0 &&
@@ -3677,7 +3726,7 @@ msk_init_locked(struct msk_if_softc *sc_if)
 	/* Configure hardware VLAN tag insertion/stripping. */
 	msk_setvlan(sc_if, ifp);
 
-	if (sc->msk_hw_id == CHIP_ID_YUKON_EC_U) {
+	if ((sc_if->msk_flags & MSK_FLAG_RAMBUF) == 0) {
 		/* Set Rx Pause threshould. */
 		CSR_WRITE_1(sc, MR_ADDR(sc_if->msk_port, RX_GMF_LP_THR),
 		    MSK_ECU_LLPP);
@@ -3790,6 +3839,8 @@ msk_set_rambuffer(struct msk_if_softc *sc_if)
 	int ltpp, utpp;
 
 	sc = sc_if->msk_softc;
+	if ((sc_if->msk_flags & MSK_FLAG_RAMBUF) == 0)
+		return;
 
 	/* Setup Rx Queue. */
 	CSR_WRITE_1(sc, RB_ADDR(sc_if->msk_rxq, RB_CTRL), RB_RST_CLR);
diff --git a/sys/dev/msk/if_mskreg.h b/sys/dev/msk/if_mskreg.h
index ba0d730..c0bd90e 100644
--- a/sys/dev/msk/if_mskreg.h
+++ b/sys/dev/msk/if_mskreg.h
@@ -2158,6 +2158,7 @@ struct msk_stat_desc {
 
 #define MSK_TX_RING_CNT		256
 #define MSK_RX_RING_CNT		256
+#define	MSK_RX_BUF_ALIGN	8
 #define MSK_JUMBO_RX_RING_CNT	MSK_RX_RING_CNT
 #define	MSK_STAT_RING_CNT	((1 + 3) * (MSK_TX_RING_CNT + MSK_RX_RING_CNT))
 #define MSK_MAXTXSEGS		32
@@ -2307,6 +2308,7 @@ struct msk_softc {
 	uint32_t		msk_coppertype;
 	uint32_t		msk_intrmask;
 	uint32_t		msk_intrhwemask;
+	uint32_t		msk_pflags;
 	int			msk_suspended;
 	int			msk_clock;
 	int			msk_msi;
@@ -2348,6 +2350,8 @@ struct msk_if_softc {
 	int			msk_phytype;
 	int			msk_phyaddr;
 	int			msk_link;
+	uint32_t		msk_flags;
+#define	MSK_FLAG_RAMBUF		0x0010
 	struct callout		msk_tick_ch;
 	int			msk_watchdog_timer;
 	uint32_t		msk_txq;	/* Tx. Async Queue offset */